For those not familiar with Giff Gaff, they are one of the main MVNOs (Mobile Virtual Network Operator) and they piggy back off the O2 infrastructure.

Here's the content of their latest blog highlighting this change

Summer has finally arrived and we've decided to celebrate - so we’re happy to announce that as of next week - 12th of June – we will be doubling the minutes on our £10 goodybag. From this date onwards, you will get 500 minutes (instead of the usual 250) plus unlimited texts and 1GB of data for £10.

This is a limited offer for new joiners ending on 31st of October 2013, however the great news is that all existing members will also benefit AND be able to continue using this offer past that date.

We’re letting you know a week early so you can time the purchase of your new goodybag. If you have set your goodybag to recur or you've queued one up to start on or after 12th of June we’ll include the extra 250 minutes automatically.

There does appear to be one caveat though:

The offer is open to everyone up until 31st October. After that date all existing members will continue to be able to select the goodybag with extra minutes, however members joining after this date will not.

So all in all, a cracking deal now with 500 mins for £10/month and a rolling PAYG style 30 day commitment. This change certainly appears to fill a hole in their range for people wanting more minutes without having to pay for the expense of unlimited data too.

Sign up here: Giff Gaff Sign-Up and you'll get £5 extra credit for free when you activate your SIM.

I think their tariffs are really fair now and give great coverage of uses. If you wanted more minutes in the past you had to pay for unlimited web as well. Not everyone uses or needs unlimited web. I'd suggest there's plenty of people who don't use 500MB a month, me being one of them as i'm never away from Wi-Fi or a proper computer.